Speed up CheckHighForm (bp #1582) (#1583)

* Lazily generate more detailed error messages in CheckHighFormLike

Don't serialize Expressions unless there is an error

(cherry picked from commit 8576a68e)

* Don't check Types of Expressions in CheckHighFormLike

Expression Types are derived. They cannot cause the errors detected by
CheckHighFormLike independently of the user-specified types that remain
chedked. This speeds up CheckChirrtl and CheckHighForm substantially.

(cherry picked from commit 6910d3fb

)

Co-authored-by: Jack Koenig <koenig@sifive.com>